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Corresponding author: Rita de Cssia Lazzarini Dutra, Diviso de Qumica - AQI, Instituto de Aeronutica e Espao IAE,Av. Marechal do Ar Eduardo Gomes, 50, Vila das Accias, CEP 12228-904, So Jos dos Campos, SP, Brasil, e-mail: [email protected]

http://dx.doi.org/10.4322/polimeros.2014.066

Characterization of Additives Typically Employed in EPDMFormulations by Using FT-IR of Gaseous Pyrolyzates

Natlia Beck SanchesInstituto Tecnolgico de Aeronutica ITA

Silvana Navarro CassuInstituto Tecnolgico de Aeronutica ITA

Diviso de Qumica AQI, Instituto de Aeronutica e Espao IAE

Milton Faria DinizDiviso de Qumica AQI

Instituto de Aeronutica e Espao IAE

Rita de Cssia Lazzarini DutraInstituto Tecnolgico de Aeronutica ITA

Diviso de Qumica AQI, Instituto de Aeronutica e Espao IAE

Abstract: In this study, Fourier transform infrared spectroscopy (FT-IR) was employed to investigate the gaseouspyrolysis products of ethylenepropylenediene rubber (EPDM). The objective was to evaluate the potential of FT-IRanalysis of gaseous pyrolyzates (PY-G/FT-IR) for characterization of EPDM additives. Two EPDM formulations,containing additives typically employed in EPDM rubbers, were analyzed. Initially, gaseous pyrolysis productsfrom paraffin oil, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline, tetramethylthiuram monosulfide (TMTM),tetramethylthiuram disulfide (TMTD), and 2-mercaptobenzothiazole (MBT) were characterized separately, and theirmain absorptions were identified. Subsequently, the gaseous pyrolysis products of raw, unvulcanized, and vulcanizedEPDM formulations were analyzed. The similarities observed in the FT-IR spectra of unvulcanized and vulcanizedEPDM show that the vulcanization process does not interfere with the pyrolysis products. The identification of thefunctional groups of the studied additives was possible in both unvulcanized and vulcanized EPDM samples, withoutsolvent extraction. Results also demonstrate that the PY-G/FT-IR technique can identify additives containing sulfur in

concentrations as low as 1.4 phr (1.26%) in both unvulcanized and vulcanized EPDM. However, the method showedsome limitation due to overlapping and to similarities of TMTM and TMTD PY-G/FT-IR spectra, which could notbe distinguished from each other. The PY-G/FT-IR technique is a faster and cheaper alternative to the sophisticatedtechniques usually applied to detection of additives in rubbers.

Keywords:EPDM, gaseous pyrolyzates, additives, characterization, FT-IR.

Introduction

The detection of polymeric additives is a matter ofgreat relevance because it enables the reconstructionof formulations in unknown rubbers, the solving

of manufacturing problems, the investigation of acompetitors compounds and the realization of qualitystudies[1].

Low molecular weight chemical compounds, knownas additives, are incorporated in to rubbers to obtaindesirable properties[2]. The main additives used in rubbersare antioxidants, vulcanizing agents, accelerators,reinforcing agents, activators, and processing aids.Many kinds of compounds can be employed to performthe same function. For example, dithiocarbamates,benzothiazoles, amines, thioureas, and thiuram disulfides

can all act as accelerators[3]. Additives are selected basedon the rubber vulcanization system and intended finalproperties.

Additive analysis can be challenging because ofthe complex and tedious process of isolating additivesfrom compounded rubber[4]. Some methods require

solvent extraction, which may cause chemicals changesand interferences between the solvent and additives.This should be taken into consideration when choosinganalytical methodology for additive determination.Hence, the use of techniques that allow for analysis ofadditives without prior separation from the polymer isalways preferred.

There are many sample preparation techniquessuitable for studying polymers. The pyrolysis technique,which consists of decomposing the molecule into volatilefragments via thermal energy, has been extensively

used[5]. It can be applied to study polymers by assessingtheir thermal behavior or by studying the pyrolysisproducts.

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Sanches, N. B. et al. -Characterization of additives typically employed in EPDM formulations by using FT-IR of gaseous pyrolyzates

The analysis of pyrolysis products can clarifythe composition of a polymer, because the obtainedfragments are related to the fundamental structure of theoriginal macromolecule.

Several studies have been published about polymerand additive analysis using the pyrolysis technique[5-10].

Typically, the analytical techniques used to identifythe fragments from pyrolysis are gas chromatography(GC) and mass spectrometry (MS). The coupling ofthese techniques has been applied for many years in thecharacterization of organic compounds[6,11-16].

Among the various additives used in a rubber system,the analysis of sulfur compounds can be particularlycomplex. More than one method is typically employedand the results are correlated, because no single techniquecan provide a complete evaluation of these compounds.Some of the methods used to identify accelerators andantioxidants containing sulfur compounds are GC/MS,

thermal desorption (TD)-GC/MS, high-performanceliquid chromatography, and thin-layer chromatography.Generally, these methods require solvent extraction of theadditives and are time-consuming[17].

In the literature, only a few studies have employedFourier transform infrared analysis of gaseous pyrolyzates(PY-G/FT-IR) for rubber characterization. Nunes et al.[18] compared the results of a tracking resistance testand PY-G/FT-IR analysis to study the degradationmechanisms of EPDM rubber. They identified ethene,methane, CO, and CO

2as the products of EPDM pyrolysis.

Matheson et al.[19] used PY-G/FT-IR to determine the

polymer content in carbon-filled natural rubber (NR) andstyrenebutadiene rubber (SBR). They concluded thatNR/SBR rubbers can be analyzed by PY-G/FT-IR withno interference from the carbon black load up to 35%.Fernndez-Berridi et al.[20] used PY-G/FT-IR and high-resolution thermogravimetric analysis (Hi-Res TGA)to determine the elastomer content of SBR/NR in usedtires. Both techniques were found to be adequate forperforming compositional analysis of vulcanizates, butHi-Res TGA was unable to determine the relative contentof styrene and butadiene in the SBR samples. Eventhough the PY-G/FT-IR technique was used, none of

the cited studies applied infrared spectroscopy to detectadditives in gaseous products after rubber pyrolysis.

In a previous work[21], PY-G/FT-IR was applied toinvestigate vulcanized elastomers with additives that hadbeen previously extracted with solvents. Several rubbersand rubber blends were identified from the gaseousproducts yielded during pyrolysis. The aim of that studywas to identify the polymeric matrix.

The present study focused on the detection ofadditives in EPDM rubber by PY-G/FT-IR, withoutprior extraction. FT-IR spectra of raw, unvulcanized,and vulcanized EPDM can provide different and

complementary information; therefore their PY-G/FT-IRspectra were also assessed. Raw rubber was analyzed as areference sample, and its FT-IR spectrum was comparedto the spectra of unvulcanized and vulcanized EPDMto distinguish polymer-only absorptions. Unvulcanizedrubber was analyzed to obtain the spectra prior to thevulcanization process, when additives are supposed

to be chemically preserved. Qualitative analysis wasperformed, focusing only on the detection or not of theadditives bands.

Experimental

Materials

The additives paraffin oil, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), tetramethylthiurammonosulfide (TMTM), and 2-mercaptobenzothiazole(MBT) were characterized individually as received.

Commercial grade EPDM Keltan 21, containingthe diene ENB (ethylidene norbornene), from DSMElastmeros do Brasil Ltda, Brazil, was used in this studyas received, without additives (raw rubber). The neatrubber was used as a reference sample.

Unvulcanized and vulcanized samples (sampleterminology is in accordance with the ASTM D1566-

11[22]) were prepared using EPDM Keltan 21 and rubbergrade chemicals, according to compositions A and Bshown in Table 1. Composition B follows formula No. 1from the Standard ASTM D3568-03[23], which applies to

Table 1. Composition of EPDM rubber.

Component SAMPLE A

Unvulcanized and

Vulcanized(phra)

SAMPLE B

Unvulcanized and

Vulcanized (phra)

EPDM Keltan 21 100 100

Paraffin oil 1.0 50.0

Stearic acid 0.5 1.0

TMQ 1.0 0

TMTM 0.7 0

TMTD 0 1.0

MBT 0.7 0.5

ZnO (Zinc oxide) 2.0 5.0

Carbon black 5.0 80.0

S (Sulfur) 0.7 1.5aparts per hundred parts of rubber.

Figure 1. Molecular structure of the analyzed compounds priorto pyrolysis.

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general purpose EPDM types. The molecules of thecompounds prior to pyrolysis are shown in Figure 1.

Pyrolysis

Each additive was weighed as received, placed in apyrolysis tube, and pyrolyzed individually with a Bunsenburner. The gas that evolved was trapped in a preheatedgas cell, as described in a previous study[21]and directlyanalyzed by FT-IR.

Raw, unvulcanized, and vulcanized EPDM were cutinto small pieces and pyrolyzed separately, as describedabove. The gaseous pyrolyzates were analyzed by FT-IR.

Infrared spectroscopy

FT-IR was carried out with a PerkinElmer SpectrumOne spectrometer. Spectra were collected with4 cm1 resolution and an average of 20 scans over the

wavenumber range 4000500 cm1 in transmissionmode.

Results and Discussion

Pyrolysis is a valuable sample preparation techniquethat yields complex and rich information. Depending onthe substance and pyrolysis conditions, the result maycontain gaseous, liquid, and solid products. In this work,only the gaseous phase was analyzed by FT-IR, which isa powerful tool for identification and characterization ofgaseous pyrolysis products[24]. Peaks observed in the FT-IR

spectrum differ depending on the physical state of themolecule. The changes in the band shape and peak shiftsmay occur because of fewer intermolecular interactionsin the gas phase than liquid or solid phases [25,26].

Generally, an exact identification of all the detectedbands is neither possible nor necessary. A more productiveapproach is to search for evidence of the presence orabsence of characteristic functional groups[24,25,27]. In this

study, this practice was used for the assignment of peaksin the PY-G/FT-IR spectra.

Infrared analysis of additives

The final properties of rubber are determined byadditives. Therefore, it is essential to characterize alladditives prior to mixing them into the rubber compoundto ensure the right compounds are being employed. Forthis reason, paraffin oil, stearic acid, TMQ, TMTM,TMTD, and MBT additives were analyzed separately byPY-G/FT-IR. The FT-IR spectra of the gaseous pyrolysisproducts are shown in Figure 2. Spectra of additives in theoriginal state are available on the BIO-RAD/SADTLERReference Database[28].

The main bands observed in the FT-IR spectrumof the gaseous pyrolysis products from paraffin oil are1219 and 771 cm1 (Figure 2a). The band observed at

1219 cm

1

can be attributed to the CH3group. The bandat 771 cm1 can be attributed to the CH2 group and/or

CH aromatic group[27]. However, paraffin oil does notcontain any aromatic groups, but rubber grade paraffinoils are mixtures of paraffin oil (50%68%), naphthenicoil (26%40%), and aromatic oil (2%7%). Hence, C=Cand C-H of the aromatic groups and the CH

2 and CH

3

groups would be present in rubber grade paraffin oils.The absorption that can be attributed to aromatic groupsis verified at 771 cm1.

The FT-IR spectrum of stearic acids gaseous pyrolysisproducts is shown in Figure 2a. The band at 771 cm1, the

peak at 1738 cm1

, and the band at 1219 cm1

is attributedto the CH2, C=O, and C-O group, respectively[26].

The FT-IR spectrum of the gaseous pyrolysis productsof the antioxidant TMQ is presented in Figure 2a. Theband at 1303 cm1 can be attributed either to the N-Hgroup[25] or/and to the C-N group[27]. The peaks in theregions of 31483014 cm1and 771 cm1 are attributedto C-H aromatic groups or/and N-H[25]. The bands at

Figure 2. PY-G/FT-IR spectra of (a) additives without sulfur; and (b) additives containing sulfur.

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29682889 cm1and 1355 cm1are typical of CH3groups,

and the peak at 1269 cm1is attributed to C-N aromaticgroup.

During pyrolysis of TMQ, it is possible that cleavageof the hydrogen-nitrogen bond and the CCH

3 groups

occurs. The aromatic rings presumably are stable because

of resonance. The main degradation products of TMQdetermined in the literature[29] are as follows: p,p-diamino-2,2-diphenylpropane, methyl, and smallquantities of aniline, whose chemical structures containgroups that can be related to the absorptions observed inthe TMQ spectrum (Figure 2a).

Figure 2b shows the FT-IR spectrum of the gaseouspyrolysis products of sulfur compounds. TMTM spectrumshows bands at 29682889 cm1, which are attributed tothe CH

3group. The band at 2075 cm1can be probably

attributed to the N=C=S (isothiocyanate) group[27].

Spectra of CS2 in the gaseous state, obtained fromreference databases[28,30], show absorptions at 2320,2180, and 1530 cm1, which are similar to absorptions at23322319, 21922178, and 15401525 cm1 detectedin the PY-G/FT-IR spectrum of TMTM. Hence, CS

2is a

pyrolysis product of this additive. These absorptions canalso be attributed to the presence of the C=S group.

Figure 2b also shows the FT-IR spectrum for thegaseous pyrolysis products of TMTD, which presentabsorptions similar to TMTM. These results wereexpected because the two molecules have similar

structures. The TMTD molecule has two atoms of sulfurwhile TMTM has only one. The SS bond of TMTDwas not detected in the FT-IR spectrum, probablybecause its vibration is very weak[27]. According toNieuwenhuizen[31], TMTD decomposes by heat intoTMTU (1,1,3,3-tetramethylthiourea), CS

2, and sulfur.

Considering that the element sulfur is the only pyrolysisproduct of TMTD that is different from TMTM and thatatomic sulfur is not detectable by infrared, it was expectedthat the TMTD spectrum would have the same bands asthe TMTM spectrum.

The last additive analyzed was the MBT accelerator.

According to Contini et al.[32], MBT exists in itstautomeric thione (benzothiazoline-2-thione) form inthe vapor phase. The thione form has a C=S bond anda hydrogen atom bonded to the nitrogen instead of thesulfur and endocyclic C=N bond (thiol form). According

Figure 3. PY-G/FT-IR spectra of EPDM. (a) raw, (b) Sample A - unvulcanized and vulcanized, and (c) Sample B - unvulcanized andvulcanized.

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Table 2. Bands in the PY-G/FT-IR spectra of EPDM rubbers related to the additives.

EPDM Sample Wavenumber (cm1)

Raw EPDM - - - -

Sample A Unvulcanized 2192-2179 (W) 2071-2047 (W) 1540-1525 (S) 771 (W)

Vulcanized 2192-2179 (W) 2071-2047 (W) 1540-1525 (S) 771 (W)

Sample B Unvulcanized 2192-2179 (W) 2071-2047 (W) 1541-1527 (S) 772 (W)

Vulcanized 2192-2179 (W) 2071-2047 (W) 1541-1526 (S) 772 (W)

Paraffin Oil - - - 771 (M)

TMQ - - - 771 (W)

Stearic Acid - - - 772 (S)

TMTM 2192-2178 (S) 2075(M) 1540-1525 (S) 771 (W)

TMTD 2192-2178 (S) 2070-2052(M) 1546-1525 (S) 771 (W)

MBT 2192-2178(W) 2071-2051 (W) 1540-1525 (S) 771 (W)

to Wu et al.[33]and Mohamed et al.[34], thione is also thedominant form in the solid state.

The FT-IR spectrum for the gaseous pyrolysisproducts of MBT is presented in Figure 2b. The peak at771 cm1is attributed to the C-H aromatic group.

The spectrum of MBT, like the spectrum of TMTM,

shows a strong doublet at 15401525 cm1. Weakdoublets were also detected at 23322319 cm1 and21922178 cm1. All three doublets can be assignedto CS

2 and/or the C=S group analogous to the TMTM

assignment. This assignment is associated with the thioneform cited by Contini[32].

Taking the assignments of the additives spectra intoconsideration, all the additives can be differentiated fromeach other using the FT-IR spectra of gaseous pyrolyzates,except the TMTM and TMTD thiuram accelerators.Moreover, the additives containing sulfur are easilydistinguished from the others by detection of doublets in

the regions 23322319, 21922178, and 1540-1525 cm1.This can be very helpful in the investigation of anunknown rubber, because the PY-G/FT-IR technique canreadily indicate whether or not a sulfur compound wasincorporated in the rubber.

Infrared analysis of EPDM samples

The FT-IR spectra of the gaseous pyrolysis productsof raw, unvulcanized, and vulcanized EPDM are shownin Figure 3. The absorptions detected in the gaseouspyrolyzates of the raw EPDM FT-IR spectrum are relatedexclusively to the EPDM chain, because no additives were

added to this sample. The peak at 3086 cm1is attributedto the C-H olefinic and/or aromatic. The peaks at 988 and911 cm1 were attributed to the C=C vinyl group. Theband around 949 cm1was attributed to C=C trans bonds.The bands observed at 889 cm1and at 1385 cm1wereattributed to the RRCCH

2group and to the CH

3group,

respectively. The assignments are in accordance with apublished study[6], which evaluated the ENB content inEPDM rubber by PY-GC/MS. These results indicate amix of alkanes and alkenes among the major pyrolysisproducts of EPDM rubber.

Additionally, spectra of unvulcanized and vulcanized

EPDM (Figures 3b, c) showed doublets around21922179, 20712047, and 15401525 cm1, and a band

at 771 cm1. These peaks were absent in the PY-G/FT-IRspectrum of the raw EPDM (Figure 3a) and thus arerelated to the additives.

To evaluate the main absorptions from the additivesin the FT-IR spectra and to establish their connectionto the bands observed in the PY-G/FT-IR spectra of

unvulcanized and vulcanized EPDM, the most importantFT-IR absorptions are summarized in Table 2. Bandintensities are indicated as follows: S for strong, M formedium, and Wfor weak.

As can be seen in Table 2, none of the peaksdetected in the PY-G/FT-IR spectra of the additiveswere seen in the PY-G/FT-IR spectrum of raw EPDM,as expected. Unvulcanized and vulcanized samples havesimilar absorption bands. The doublets in the region of21922178 cm1 and 15401525 cm1 can be attributedto the additives TMTM, TMTD, and MBT, all containingsulfur in their molecular structure. The peak in the regionof 771 cm1 can be associated with all of the analyzedadditives.

Modifications occurring during the vulcanizationreaction can make detection of additives in rubbersvery difficult. The additives can be chemically alteredwith heat and simultaneous reactions. In theory, resultsobtained from the same rubber can be different beforeand after vulcanization. Nevertheless, these differenceswere not observed in this study as the PY-G/FT-IRspectra of unvulcanized and vulcanized rubber weresimilar.

Usually, infrared absorption of sulfur compoundsin solid and liquid state is weak[31]. Generally, it isnecessary to use complementary techniques, such asRaman spectroscopy, to detect them. In this study, as thegaseous pyrolyzate was analyzed, the absorptions relatedto the sulfur compound in the gaseous state showedstronger intensity. PY-G/FT-IR detected concentrationsof MBT and TMTM or TMTD as low as 1.4 phr (1.26%),confirming the potential of this technique to be appliedfor detection of sulfur compounds. Even the spectrumof vulcanized EPDM, whose additives are supposedto be largely consumed in the crosslinking process,

showed strong bands in the gaseous pyrolyzate that wereattributed to sulfur compounds.

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Table 3 shows the association of the pyrolysis products

found in the literature with the functional groups assigned

in this study for each of the compounds analyzed.

In Table 3, the referenced studies usually employed

PY/GC and/or PY/GC/MS techniques to determine the

degradation products. These techniques have the merit

of performing separation of the decomposition products

prior to their identification. In this study, even though

the employed PY-G/FT-IR technique does not separate

the evolving pyrolyzates, identification of the functional

groups in the EPDM samples was possible. Furthermore,

by correlating the data presented for each compound in

Table 3, it is evident that the functional groups assigned

by PY-G/FT-IR are related to the pyrolysis products in

the literature.

The technique PY-G/FT-IR used in this study is faster

and cheaper than other techniques because pyrolysis

was performed using a Bunsen burner without additive

extraction. Moreover, FT-IR is a more affordable

technique than GC and/or MS techniques. A laboratorywithout sophisticated equipment can take advantage

of this simple, rapid, and inexpensive technique, as

an alternative option, to characterize and develop

compounds, reconstruct formulations, and perform

quality control.

Conclusion

The characterization of additives frequently usedin EPDM rubber was performed using the PY-G/FT-IRtechnique, which was capable of distinguishing allthe additives from each other, except the TMTM andTMTD thiuram accelerators, which presented similarFT-IR spectra. Moreover, these sulfur additives showedcharacteristic absorptions enabling their differentiationfrom additives without sulfur.

The PY-G/FT-IR technique was applied to thestudy of unvulcanized and vulcanized EPDM samples.The technique was able to detect absorptions of sulfuradditives present in EPDM rubber in concentrations aslow as 1.4 phr (1.26%), even in vulcanized samples.The characteristic groups of all studied additives wereidentified in unvulcanized and vulcanized EPDM, evenwithout their previous extraction using solvents. Somelimitations in the method were observed because of theabsorbance band overlap.

The PY-G/FT-IR technique used in this study is lesstime-consuming and expensive than other techniquesapplied for the investigation of rubber compounding, and

it can be employed for the analysis of separate additives,neat rubber (raw), and unvulcanized and vulcanizedcompounds.

These findings are valid for the studied formulations.Further investigation would be necessary to verifywhether the methodology is suitable for others rubbersand additives formulations.

Table 3. Components and pyrolysis products from the literature and functional groups assigned in this study.

Component Pyrolysis Products

(from literature)

Functional Groups assigned in

this study by PY-G/FT-IR

EPDM Propylene, propane, butane, 1-hexene, 1-heptene,benzene, toluene, 4-ethylidene-1-cyclopentene, and

3-ethylidene-1-cyclopentene[6]

C=C vinyl

C=C trans

RRCCH2

CH3

C-H olefinic and/or aromatic

Paraffin Oil Hydrocarbon chains from C20to C34[8]. CH3

CH2and/or C-H aromatic

Stearic Acid Alkenes from C3 to C

17and large amount of vaporized

stearic acid[8]CH

2

C=O

C-O

TMQ Aniline, methyl, TMQ,

p,p-diamino-2,2-diphenylpropane[29]N-H

C-H aromatic

C-N

CH3C-N aromatic

TMTM TMTU, CS2[31] CS2and/or C=S

CH3

N=C=S

TMTD TMTU, CS2, sulfur[31] CS

2and/or C=S

CH3N=C=S

MBT Benzothiazoline-2-thione 27[33] CS2and/or C=S

C-H aromatic

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References

1. Raemaekers, K. G. H. & Bart, J. C. J. - Thermoch.Acta, 295, p.1 (1997). http://dx.doi.org/10.1016/S0040-6031(97)00097-X

2. avdar, S.; zdemir, T. & Usanmaz, A. - Plast. Rubber

Compos., 39, p.277 (2010). http://dx.doi.org/10.1179/174328910X12647080902970

3. Fishbein, L. - Scand J Work Environ Health, 9, p.7 (1983).PMid:6356341.

4. Buchberger, W. & Stftinger, M. - Adv. Polym. Sci., 248,p.39 (2012). http://dx.doi.org/10.1007/12_2011_147

5. Wampler, T. P. - Applied Pyrolysis Handbook, CRCPress, Boca Raton (2007).

6. Choi, S. & Kim, Y. - Polym. Test., 30, p.509 (2011). http://dx.doi.org/10.1016/j.polymertesting.2011.04.005

7. Hiltz, J. A. - J. Appl. Pyrolysis, 55, p.135 (2000). http://

dx.doi.org/10.1016/S0165-2370(99)00090-X8. Wang, F. C. & Buzanowski, W. C. - J. Chromatogr.

A, 891, p.313 (2000). http://dx.doi.org/10.1016/S0021-9673(00)00648-8

9. Jansson, K. D.; Zawodny, C. P. & Wampler, T. P. - J. Appl.Pyrolysis, 79, p.353 (2007). http://dx.doi.org/10.1016/j.

jaap.2006.12.009

10. Kusch, P. - Spectroscopy (2012).

11. Sobeih, K. L.; Baron, M. & Gonzales-Rodriguez, J. - J.Chromatogr. A, 1186, p.51 (2008). PMid:17980891. http://dx.doi.org/10.1016/j.chroma.2007.10.017

12. Kim, S. W.; Heo, G. S. & Lee, G. H. - Anal. Sci., 13,p.257 (1997). http://dx.doi.org/10.2116/analsci.13.Supplement_257

13. Smith, P. B.; Pasztor, A. J.; McKelvy, M. L.; Meunier, D.M.; Froelicher, S. W. & Wang, F. C. Y. - Anal. Chem., 71,p.61 (1999). http://dx.doi.org/10.1021/a1990004f

14. Blazs, M. - J. Anal. Appl. Pyrolysis, 39, p.1 (1997). http://dx.doi.org/10.1016/S0165-2370(96)00956-4

15. Alekseeva, K. V. - J. Anal. Appl. Pyrolysis, 2, p.19 (1980).http://dx.doi.org/10.1016/0165-2370(80)80042-8

16. Jimnez, A. & Ruseckaite, R. A. - Pyrolysis-GC/MS

techniques for polymer characterization and degradationin: Encyclopedia of Chromatography, cap. 298, Jack Cazes(ed.), Taylor & Francis, Boca Raton (2005).

17. Bart, J. C. J. - Additives in polymers: industrial analysisand applications, John Wiley & Sons, Chichester (2005).http://dx.doi.org/10.1002/0470012064

18. Nunes, S. P.; Costa, R. A.; Barbosa, S. P.; Almeida, G. R. &Galembeck, F. - IEEE Trans Electr Insul., 24, p.99 (1989).http://dx.doi.org/10.1109/14.19871

19. Matheson, M. J.; Wampler, T. P. & Simonsick, W. J. - J.Anal. Appl. Pyrolysis, 29, p.129 (1994). http://dx.doi.

org/10.1016/0165-2370(94)00791-8

20. Fernndez-Berridi, M. J.; Gonzlez, N.; Mugica, A. &

Bernicot, C. - Thermochim. Acta, 444, p.65 (2006). http://

dx.doi.org/10.1016/j.tca.2006.02.027

21. Sanches, N. B.; Diniz, M. F.; Reis, T. B.; Cassu, S. N. &

Dutra, R. C. L. - Polmeros, 16, p.211 (2006). http://dx.doi.

org/10.1590/S0104-14282006000300010

22. American Society for Testing and

Materials - ASTM. - D1566: standard terminology relating

to rubber, ASTM, Philadelphia (2011).

23. American Society for Testing and

Materials - ASTM. - D3568: standard test methods for

rubber. Evaluation of EPDM (Ethylene Propylene Diene

Terpolymers) including mixtures with oil, ASTM,

Philadelphia (2009).

24. Socrates, G. - Infrared and raman characteristic group

frequencies: tables and charts, Wiley & Sons, Chichester

(2001).25. Welti, D. & Stephany, R. - Appl. Spectrosc., 22, p.678

(1968). http://dx.doi.org/10.1366/000370268774384119

26. Young, P. R. - Practical spectroscopy: the rapid

interpretation of spectral data, Thomson Learning, Pacific

Groove (2000).

27. Silverstein, R. M.; Webster, F. X. & Kiemle, D.

J. - Spectrometric identification of organic compounds,

John Wiley & Sons, New York (2005).

28. BIO-RAD/SADTLER Reference Database. (2013).

Disponvel em: .

29. mejkal, F.; hov, A.; Popl, M. & Novk, J. - Angew.

Makromol. Chem., 88, p.135 (1980). http://dx.doi.

org/10.1002/apmc.1980.050880111

30. National Institute of Standards and Technology NIST.

NIST Chemistry WebBook. (2013). Disponvel em: .

31. Nieuwenhuizen, P. J.; Reedijk, J.; van Duin, M. & McGill,

W. J. - Rubber Chem. Technol., 70, p.368 (1997). http://

dx.doi.org/10.5254/1.3538436

32. Contini, G.; Castro, V.; Stranges, S.; Richter, R. & Alagia,

M. - J. Phys. Chem. A, 106, p.2833 (2002). http://dx.doi.org/10.1021/jp013423b

33. Wu, F. L.; Hussein, W. M.; Ross, B. P. & McGeary, R.

P. - Curr. Org. Chem., 16, p.1555 (2012). http://dx.doi.

org/10.2174/138527212800840964

34. Mohamed, T. A.; Mustafa, A. M.; Zoghaib, W. M.; Afifi, M.

S.; Farag, R. S. & Badr, Y. - Theochem, 868, p.27 (2008).

http://dx.doi.org/10.1016/j.theochem.2008.07.037

Received: 09/26/13

Revised: 02/12/14

Accepted: 03/13/14

Polmeros, vol. 24, n. 3, p. 269-275, 2014 275
http://dx.doi.org/10.1016/S0040-6031(97)00097-Xhttp://dx.doi.org/10.1016/S0040-6031(97)00097-Xhttp://dx.doi.org/10.1179/174328910X12647080902970http://dx.doi.org/10.1179/174328910X12647080902970http://dx.doi.org/10.1007/12_2011_147http://dx.doi.org/10.1016/j.polymertesting.2011.04.005http://dx.doi.org/10.1016/j.polymertesting.2011.04.005http://dx.doi.org/10.1016/S0165-2370(99)00090-Xhttp://dx.doi.org/10.1016/S0165-2370(99)00090-Xhttp://dx.doi.org/10.1016/S0021-9673(00)00648-8http://dx.doi.org/10.1016/S0021-9673(00)00648-8http://dx.doi.org/10.1016/j.jaap.2006.12.009http://dx.doi.org/10.1016/j.jaap.2006.12.009http://dx.doi.org/10.1016/j.chroma.2007.10.017http://dx.doi.org/10.1016/j.chroma.2007.10.017http://dx.doi.org/10.2116/analsci.13.Supplement_257http://dx.doi.org/10.2116/analsci.13.Supplement_257http://dx.doi.org/10.1021/a1990004fhttp://dx.doi.org/10.1016/S0165-2370(96)00956-4http://dx.doi.org/10.1016/S0165-2370(96)00956-4http://dx.doi.org/10.1016/0165-2370(80)80042-8http://dx.doi.org/10.1002/0470012064http://dx.doi.org/10.1109/14.19871http://dx.doi.org/10.1016/0165-2370(94)00791-8http://dx.doi.org/10.1016/0165-2370(94)00791-8http://dx.doi.org/10.1016/j.tca.2006.02.027http://dx.doi.org/10.1016/j.tca.2006.02.027http://dx.doi.org/10.1590/S0104-14282006000300010http://dx.doi.org/10.1590/S0104-14282006000300010http://dx.doi.org/10.1366/000370268774384119https://scifinder.cas.org/http://dx.doi.org/10.1002/apmc.1980.050880111http://dx.doi.org/10.1002/apmc.1980.050880111http://webbook.nist.gov/chemistry/name-ser.htmlhttp://webbook.nist.gov/chemistry/name-ser.htmlhttp://dx.doi.org/10.5254/1.3538436http://dx.doi.org/10.5254/1.3538436http://dx.doi.org/10.1021/jp013423bhttp://dx.doi.org/10.1021/jp013423bhttp://dx.doi.org/10.2174/138527212800840964http://dx.doi.org/10.2174/138527212800840964http://dx.doi.org/10.1016/j.theochem.2008.07.037http://dx.doi.org/10.1016/j.theochem.2008.07.037http://dx.doi.org/10.2174/138527212800840964http://dx.doi.org/10.2174/138527212800840964http://dx.doi.org/10.1021/jp013423bhttp://dx.doi.org/10.1021/jp013423bhttp://dx.doi.org/10.5254/1.3538436http://dx.doi.org/10.5254/1.3538436http://webbook.nist.gov/chemistry/name-ser.htmlhttp://webbook.nist.gov/chemistry/name-ser.htmlhttp://dx.doi.org/10.1002/apmc.1980.050880111http://dx.doi.org/10.1002/apmc.1980.050880111https://scifinder.cas.org/http://dx.doi.org/10.1366/000370268774384119http://dx.doi.org/10.1590/S0104-14282006000300010http://dx.doi.org/10.1590/S0104-14282006000300010http://dx.doi.org/10.1016/j.tca.2006.02.027http://dx.doi.org/10.1016/j.tca.2006.02.027http://dx.doi.org/10.1016/0165-2370(94)00791-8http://dx.doi.org/10.1016/0165-2370(94)00791-8http://dx.doi.org/10.1109/14.19871http://dx.doi.org/10.1002/0470012064http://dx.doi.org/10.1016/0165-2370(80)80042-8http://dx.doi.org/10.1016/S0165-2370(96)00956-4http://dx.doi.org/10.1016/S0165-2370(96)00956-4http://dx.doi.org/10.1021/a1990004fhttp://dx.doi.org/10.2116/analsci.13.Supplement_257http://dx.doi.org/10.2116/analsci.13.Supplement_257http://dx.doi.org/10.1016/j.chroma.2007.10.017http://dx.doi.org/10.1016/j.chroma.2007.10.017http://dx.doi.org/10.1016/j.jaap.2006.12.009http://dx.doi.org/10.1016/j.jaap.2006.12.009http://dx.doi.org/10.1016/S0021-9673(00)00648-8http://dx.doi.org/10.1016/S0021-9673(00)00648-8http://dx.doi.org/10.1016/S0165-2370(99)00090-Xhttp://dx.doi.org/10.1016/S0165-2370(99)00090-Xhttp://dx.doi.org/10.1016/j.polymertesting.2011.04.005http://dx.doi.org/10.1016/j.polymertesting.2011.04.005http://dx.doi.org/10.1007/12_2011_147http://dx.doi.org/10.1179/174328910X12647080902970http://dx.doi.org/10.1179/174328910X12647080902970http://dx.doi.org/10.1016/S0040-6031(97)00097-Xhttp://dx.doi.org/10.1016/S0040-6031(97)00097-X

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